This invention is directed to a device to treat the neighboring teeth to a gap in the teeth for placement of a dental bridge that replaces at least one missing tooth. Included is a treatment tool to remove the tooth material, in particular a grinding tool, and a mounting fixture that is fastened to the patient's teeth, to which an adjustable positioning device is attached to position the treatment tool. This mounting fixture has a sliding guide with a sled that shifts relative to the mounting fixture and guide rails or guide pins that guide the treatment tool.
From DE-PS 684 665, a device of this general type is already known, in which a drag bearing is located between the mounting fixture and the sliding guide. With the help of this drag bearing, the sliding guide is connected to the mounting fixture and tilts about a pivot axis oriented approximately at right angles to the plane of the chewing surface of the teeth with the device in the working position. The drag bearing has a pivot axis solidly connected to the mounting fixture on which a bushing is located which rotates and shifts axially. The sliding guide is connected to the bushing.
To install a dental bridge, the device is first fastened to the patient's teeth using the mounting fixture. Then, the teeth neighboring the gap to be bridged are ground with the device and brought to a form that is suitable for an anchoring of the dental bridge to the neighboring teeth. During this, the treatment tool is guided exactly parallel at the sled. The form in which the neighboring teeth are brought is dependent on the form of the anchoring elements provided for the dental bridge.
Then, holes are made in the teeth neighboring the gap to be bridged to set in pins that serve to anchor the dental bridge. To this end, the treatment tool guided by the sled is first placed in the position of the neighboring tooth provided for its respective hole, wherein the sled is tilted and/or shifted with respect to the mounting fixture into the respective position. Then, the treatment tool is sunk into the tooth material to make the hole by shifting the bushing to which the sliding guide is fastened along the pivot axis accordingly.
After all holes have been prepared, the pins are placed into the holes and with the help of a hardened dental impression material, an impression of the patient's teeth is taken. The paste-like or doughy dental impression material is filled into a strip that is U-shaped in cross section adjusted to fit the patient's teeth. This strip is then placed with the dental impression material contained therein onto the patient's teeth. After the dental impression material is hardened to a solid but still flexibly deformable mass in the oral cavity, the strip is pulled out with the dental impression material from the patient's teeth. A temporary filling is placed in the ground and drilled neighboring teeth that protects them from damage until the dental bridge is installed.
With the help of the dental impression, a dental technician prepares a model of the patient's teeth in the laboratory. A hardening material is filled into the negative form of the dental impression, which later forms the model, for example plaster of Paris. After the model hardens, the dental impression is pulled from the model and the dental bridge is manually prepared using the model. In this manner, the form of the anchoring elements of the dental bridge is individually and as exactly as possible adjusted to the form of the ground neighboring teeth.
The dental bridge thus prepared is then installed. The temporary filling is removed and then the dental bridge is placed with its anchoring elements onto the teeth neighboring the gap.
This prior-known device has the disadvantage in that it requires a number of processing steps to place and prepare the dental bridge. In particular, a dental impression must be taken and a model of the teeth must be made after making the holes in the neighboring teeth serving to anchor the dental bridge. Also, the dental bridge must be prepared using expensive manual activity and adjusted according to the model. It is also adverse that the manufacture and adjustment of the dental bridge to fit the neighboring teeth treated in advance using the device is so time-intensive that the patient must appear for at least two visits to the dentist. In the first visit, the teeth being used for the anchoring of the dental bridge are ground and the dental impression is taken, whereas in the second visit the dental bridge is placed and anchored to the neighboring teeth.